Manila: Philippine forces clashed with Muslim extremists on a southern island on Thursday, leaving seven soldiers and four militants dead, the military said.

Elite rangers battled members of the Al-Qaeda-linked Abu Sayyaf group on the troubled southern island of Basilan, with three soldiers and two insurgents also wounded in the clash.

"Firefight is ongoing as of this report," the military statement said.

It was the latest in a series of deadly clashes in the heavily forested island of Basilan, a stronghold of the Abu Sayyaf. The group was founded in the 1990s with seed money from Al-Qaeda leader Osama bin Laden.